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Think in patterns.
Solve like it’s the interview.

hand-picked DSA problems in C#, Java, Python, C++ and JavaScript. Run your code, climb the leaderboard and keep your streak alive.

Start practicing
  • 30problems
  • 12core patterns
  • 5languages
  • 2 Lakh+learners trained

Bubble sort

ArraysO(n²)Running

Compare neighbours, swap when out of order.

Inorder traversal

TreesDFSO(n)

Visit order:  

Breadth-first search

GraphsQueueO(V+E)

Level order:  

Longest common subsequence

Dynamic ProgrammingO(mn)

dp[i][j] = best length for the first i and j characters.

Browse by pattern

Master the idea once, solve the whole family.

#Title Acceptance Difficulty
1Flood Fill Recursion69.00%Medium
2Number of Islands Recursion66.00%Medium
3Binary Tree Zigzag Level Order Traversal Tree · Recursion · Traversal71.48%Medium
4Search in a 2D Matrix Recursion · Binary Search86.00%Medium
5Find Minimum In Rotated Sorted Array Recursion89.00%Medium
6Generate All Subsequence Recursion56.00%Medium
7Check if Binary Tree is Balanced Recursion77.00%Medium
8Generate All Subsets Recursion60.00%Medium
9Count Nodes in Binary Tree Recursion64.00%Medium
10Letter Combinations of Phone Number Recursion60.00%Medium
11Tiling Problem Recursion50.00%Medium
12Permutation Without Duplicates Recursion67.00%Medium
13Combination Sum II Recursion76.00%Medium
14Permutation of an Array Array · Recursion68.00%Medium
15Permutation of A String String · Recursion66.00%Medium
16Subsets with Duplicates Recursion74.00%Medium
17Count Ways To Reach Nth Stair Recursion60.00%Medium
18Friends Pairing Problem Recursion50.00%Medium
19Count Binary Strings Recursion60.00%Medium
20Fibonacci Series (Tree Recursion) Recursion60.00%Medium
21Check String Is Subsequence To Another Recursion75.00%Medium
22Convert String to Integer Recursion60.00%Medium
23Combination Sum Recursion75.00%Medium
24Word Search Recursion32.69%Medium
25Subset Sums Recursion72.55%Medium
26Distinct Paths II Array · Recursion · Dynamic Programming50.00%Medium
27Distinct Paths Array · Recursion · Dynamic Programming50.00%Medium
28Tower of Hanoi Recursion35.23%Medium
29Power Of Numbers Recursion20.22%Medium
30Sort a stack Recursion69.19%Medium

Practice that builds the habit

Three steps, repeated every day.

  1. 1

    Pick a pattern

    Start from an idea such as two pointers or BFS, then move through easy, medium and hard.

  2. 2

    Code and run

    Write in your language, run on sample cases and submit against every hidden test.

  3. 3

    Climb the board

    Every solve earns points. Keep a daily streak and see where you stand this month.

Want a plan, not just problems?

The DSA bootcamp adds structured lessons, live mentorship and mock interviews on top of this practice platform.

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